Description of Liquid Silicone RubberMC RTV silicone rubber is a two component elastomeric cross-linking
at room temperature. The polymerization can be accelerated by heat
(max. 150 C). The silicone components are delivered as liquids,
which once mixed and cured transform into a transparent, elastic
and resistant material. Polymerization occurs without formation of
heat.
Advantages of Liquid Silicone Rubber1. Easy Curing: MCPLA-H40 polymerizes at room temperature (23C).
The curing characteristics is independent of part thickness.
2. High Transparency
3. High tear and tensile strength
4. Long shelf life with low shrinkage
Applications of Liquid Silicone RubberLabel manufacturing, Molding applications requiring low shrinkage,
such as toys, jewelers, automotive, rapid prototyping etc.
Data sheet| Item No. | MCPLA-H40 |
| Appearance | Clear |
| Viscosity(cps) Part A | 40000-50000 |
| Mix ratio(by weight) | 10:1 |
| Pot Life(mins) | 90-120 |
| Curing Time(hrs) | 24 |
| Hardness(shore A) | 38-39 |
| Tensile Strength(Mpa) | 5.3 |
| Tearing Strength(KN/M) | 23 |
| Elongation(%) | >355 |
| Shrinkage(%) | 0.10 |
1. Mixing the two components
According the mixing ratio 10: 1 weighting part A and B, the two
components may be thoroughly mixed by hand or using a low speed
electric to minimize the entrance of air and to avoid any
temperature increase.
Note: It is also possible to use a special mixing and dispensing
machine for the two silicone components, further information is
available upon request.
2. Molding
The mixture should be degassed preferably at 30 to 50 mbar to
eliminate any entrapped air. If a dispensing machine is used, the
two components are degassed separately prior to mixing. The
silicone mixture expands to 3 to 4 times of its initial volume and
bubbles rise to the surface. The bubbles progressively disappear
and the mixture returns to its initial volume after 5 to 10
minutes. Wait a few minutes to complete the degassing and then
flash the vacuum. The silicone is ready for pouring, by gravity or
under low pressure.
Note: Flashing the vacuum once or twice accelerates the degassing.
It is recommended to use a container with a high diameter/height
ratio(3 to 4 times of the initial volume)
3. Polymerization
The curing may be slowed down at lower temperature or accelerated
by applying heat.
Note: In general contact with certain materials can inhibit the
cross linking of RTV.
Natural rubbers vulcanized with sulfur
RTV elastomeric is catalyzed with metal salts, e. G. Tin compounds
PVC stabilized with tin salts and additives
Epoxy catalyzed with amines
Certain organic solvents, such as Ketones, alcohols etc.
In case of doubt, it is recommended to test the substrate by
applying a small quantity of the mixed silicone on a restricted
area.Storage and shelf life of Liquid Silicone RubberMC silicone RTV must be used within 12 months from the
manufacturing date. Beyond this date, MC silicone no longer
guarantees the products confirms with the sales specification. In
order to preserve best properties it is recommended to follow
strictly the following guidelines:
Store the original packing tightly sealed and at a temperature
below 30 C
Use the product as soon as the packaging has been opened.
Packaging of Liquid Silicone Rubber
Part A: 20kg/drum; Part B: 2 kg /drum
Special containers are available are on request.
